In 1648, English king Charles I wrote four encrypted letters while in captivity on the Isle of Wight. Can a reader break these cryptograms?

Let me first proudly announce that the cover design of my next book, Codebreaking: A Practical Guide (co-written with Elonka Dunin), has now been published:

Source: Robinson

Many readers of this blog have contributed to this work, including Bill Briere, Magnus Ekhall, Thomas Ernst, Bernhard Esslinger, Dave Oranchak, Tobias Schrödel, Gerhard Strasser, Satoshi Tomokiyo, Paolo Bonavoglia, Thomas Bosbach, Jew-Lee Lann-Briere, Tony Gaffney, Jim Gillogly, Karsten Hansky, Nils Kopal, George Lasry, Richard SantaColoma, and Bart Wenmeckers. Publication is scheduled for November.

 

Unsolved cryptogram pages

One of the topics covered in this book are unsolved cryptograms. Most readers of this blog certainly know my The Top 50 unsolved encrypted messages. My co-author Elonka Dunin has a list of famous unvolved ciphertexts on her website, too.

If you are interested in unsolved machine cryptograms, check Jean-François Bouchaudy’s web-page (thanks to George Lasry for the hint).

There’s yet another page about unsolved cryptograms, and I wonder why I have never mentioned it on this blog before: Satoshi Tomokiyo’s Unsolved Historical Ciphers section, which is a part of the highly recommended Cryptiana site (also maintained by Satoshi).

Satoshi, who lives in Yokohama, Japan, was one of the proof-readers of my aforementioned codebreaking book. Elonka and I were quite impressed by his expertise in codes, nomenclators, homophonic ciphers and other encryption methods, which led to an extremely valuable feedback he provided us. And no, I don’t think that Satoshi Tomokiyo is identical with the mysterious Satoshi Nakamoto, inventor of BitCoin, though the two have the same first name.

On his Unsolved Historical Ciphers page, Satoshi writes:

Several well-known unsolved ciphers such as the Voynich Manuscript, Beale ciphers, Dorabella cipher, etc. have been attracting attention of the worldwide cryptologic community […], but historical archives (and other publications) contain many other pieces written in codes and ciphers that remain unsolved. The following lists some of such pieces in the hope that only a fraction of the efforts directed to major cryptologic puzzles might contribute to the solution of these small puzzles. (Recently broken ciphers are also listed.) The reader is kindly asked to provide information if he/she knows or attains decipherment of any of these.

Satoshi’s list contains some 60 entries, about 20 of which are solved. Some of these messages have been covered on this blog before, for instance an encoded telegram from the British consulate in Lüderitz (then German South-West Africa) to the Foreign Office in London and an unsolved Enigma message sent in 1945.

 

Charles I’s encrypted letters

On Satoshi’s list, there is a series of four messages that looks especially interesting to me: the letters written by Charles I of England (1600-1649) during his captivity on the Isle of Wight in the year 1648. Shortly after, in January 1649, Charles I was executed.

Source: Wikimedia

Details about these letters are available here on a separate page Satoshi created (the messages in question are listed as number 4).

Here’s a transcript of the first letter Charles I wrote:

Z: / I am verrie well satisfied with the discreete & carefull account that you have given me of my Business & particularly that you did 208 343 294 74 9 45 86 18 96 1 40 82 395 380 2 20 3 230 388 45 36 4 11 7 43 31 62 270 248 now it will be 36 19 5 32 39 12 37 8 97 I desyre you to enquyre whether or not 396 213 355 204 28 21 363 257 64 36 46 9 32 395 42 35 14 53 38 23 18 50 88 but for this 236 308 267 356 282 96 62 86 205 17 356 66 50 97 206 231 248 38 1 20 2 230 388 46 36 257 208 86 25 268 8 3 50 240 6 51 248 416 303 78 9 68 45 in the meane Tyme lett me know 379 4 28 5 348 354 the …. 206 18 So I rest
Your asseured Frend,
J.

According to Satoshi’s page, this letter was shown in the third episode of the BBC documentary series, Castles: Britains Fortified History. To my regret, this series appears not to be available online.

My guess is that Charles I’s letters were encrypted with a nomenclator, which makes them hard to break. If a reader knows more about this crypto mystery or even can solve it, please let me know.


Further reading: A cipher device used by king Henry II

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Kommentare (14)

  1. #1 David Oranchak
    http://zodiackillerciphers.com
    14. Juni 2020

    Someone uploaded a bootleg of “Castles: Britains Fortified History” here:

    Part 1: https://www.dailymotion.com/video/x6nvryd
    Part 2: https://www.dailymotion.com/video/x6nz26e
    Part 3: https://www.dailymotion.com/video/x6nz28d

  2. #2 Satoshi
    Yokohama
    14. Juni 2020

    Thank you for the mention!
    Klausis Krypto Kolumne is the best single source for my page. (I have to add Richelieu’s letter solved by Norbert yesterday.)
    By the way, Satoshi is quite a common first name in Japan.

  3. #3 David Oranchak
    http://zodiackillerciphers.com
    15. Juni 2020

    Here’s the clip from the show that mentions the coded letter of Charles I:

    https://www.bbc.co.uk/programmes/p02f19zb

  4. #4 David Oranchak
    http://zodiackillerciphers.com
    15. Juni 2020

    Screenshot of the coded letter:

    https://i.imgur.com/jaUAV1k.png

  5. #5 David Oranchak
    http://zodiackillerciphers.com
    15. Juni 2020

    Based on the transcript, there are 112 total numerical tokens in the letter.

    76 of them are unique. Here are the counts:

    1 (2), 2 (2), 3 (2), 4 (2), 5 (2), 6 (1), 7 (1), 8 (2), 9 (3), 11 (1), 12 (1), 14 (1), 17 (1), 18 (3), 19 (1), 20 (2), 21 (1), 23 (1), 25 (1), 28 (2), 31 (1), 32 (2), 35 (1), 36 (4), 37 (1), 38 (2), 39 (1), 40 (1), 42 (1), 43 (1), 45 (3), 46 (2), 50 (3), 51 (1), 53 (1), 62 (2), 64 (1), 66 (1), 68 (1), 74 (1), 78 (1), 82 (1), 86 (3), 88 (1), 96 (2), 97 (2), 204 (1), 205 (1), 206 (2), 208 (2), 213 (1), 230 (2), 231 (1), 236 (1), 240 (1), 248 (3), 257 (2), 267 (1), 268 (1), 270 (1), 282 (1), 294 (1), 303 (1), 308 (1), 343 (1), 348 (1), 354 (1), 355 (1), 356 (2), 363 (1), 379 (1), 380 (1), 388 (2), 395 (2), 396 (1), 416 (1)

    From most repetitive to least repetitive:

    36 (4), 9 (3), 86 (3), 50 (3), 45 (3), 248 (3), 18 (3), 97 (2), 96 (2), 8 (2), 62 (2), 5 (2), 46 (2), 4 (2), 395 (2), 388 (2), 38 (2), 356 (2), 32 (2), 3 (2), 28 (2), 257 (2), 230 (2), 208 (2), 206 (2), 20 (2), 2 (2), 1 (2), 88 (1), 82 (1), 78 (1), 74 (1), 7 (1), 68 (1), 66 (1), 64 (1), 6 (1), 53 (1), 51 (1), 43 (1), 42 (1), 416 (1), 40 (1), 396 (1), 39 (1), 380 (1), 379 (1), 37 (1), 363 (1), 355 (1), 354 (1), 35 (1), 348 (1), 343 (1), 31 (1), 308 (1), 303 (1), 294 (1), 282 (1), 270 (1), 268 (1), 267 (1), 25 (1), 240 (1), 236 (1), 231 (1), 23 (1), 213 (1), 21 (1), 205 (1), 204 (1), 19 (1), 17 (1), 14 (1), 12 (1), 11 (1)

  6. #6 Richard SantaColoma
    https://proto57.wordpress.com/2009/11/29/numerical-coding-of-word-sections/
    15. Juni 2020

    This strikes me as a word part numerical code, such as described in the 1624 Gustavus Selenus Book, “Cryptomenytices et Cryptographiae”.

    It is not the one in that book, unless this makes any sense to someone not “under the influence”:

    ensfreclipifgorustuaforapsoploexiorpspregoduohcgecumavoae

    … for that would be the first line of numbers in the OP above, using the Selenus numerical cipher. But the reason I would still think a code like this a candidate is because the numbers are in the range of the numbers of word parts as in Selenus, and also including single digits, which are used for single letters in such a system. This image shows how these codes work: https://proto57.files.wordpress.com/2009/11/selenus_sample.jpg

    A post on this cipher is linked above, in relation to the Voynich… which I still hold might be something similar to this, also.

  7. #7 David Oranchak
    http://zodiackillerciphers.com
    15. Juni 2020

    Full PDF of “The History of the Isle of Wight”, published in 1781:

    http://zodiackillerciphers.com/images/The_History_of_the_Isle_of_Wight.pdf

    Coded letter is on page 175 of the PDF (page 122 of the scanned book).

    A new edition came out in 1795: “A New, Correct, and Much Improved-history of the Isle of Wight”

    http://zodiackillerciphers.com/images/A_New_Correct_and_Much_Improved_history.pdf

    In that version the letter is on page 278 of the PDF (page 237 of the scanned book).

  8. #8 Gerry
    15. Juni 2020

    On Cryptiana there are some ciphers Charles I used in the years before his captivity http://cryptiana.web.fc2.com/code/charlesi.htm
    I think he used a similar cipher (or ciphers) in 1648/49: The low numbers up to 70 or 99 in the ciphers from 1644ff represented single letters, whereas higher numbers to about 380 were alphabetically sorted words and even higher numbers represented names.
    So the first numbers of Letter 1 could be 208=NOT and 343=TRY – but that is just a wild guess 🙂

  9. #9 Christof Rieber
    Wien
    16. Juni 2020

    Just a start but I guess the 248 is clearly the word AND. According to this, the 208 might be ASK. 9 involved should relate to the letter O, 86 possibly to ‘TH’.

    “..Business & particularly that you did ASK FOR HOW LONG TH….CRUEL….AND now it will be UP TO….I desyre (…) for this…AND…..ASK…..AND TH…”

  10. #10 Norbert
    Berlin
    16. Juni 2020

    I agree with Gerry that the numbers below 100 most likely stand for single letters.
    It is also quite possible that the plaintext words above 100 are sorted alphabetically. 379 could begin with w: “in the meane Tyme lett me know” … whether/who/what/when/why.

    In addition, one can assume that 1, 2 and 3 are homophones as well as 45 and 46:

    2 20 3 230 388 45 36
    (...)
    1 20 2 230 388 46 36

    This does not necessarily mean that all homophones are consecutive numbers for each letter, but it would be worth a try to assume that.

  11. #11 Norbert
    Berlin
    16. Juni 2020

    I think a good entry point would be:

    “now it will be 36 19 5 32 39 12 37 8 97”

    One cannot be sure, but there is a good chance that the nine codegroups represent a nine-letter adjective. How about “expedient”? Then the three e’s would correspond to 32, 36 and 37. Just a thought …

  12. #12 Klaus Schmeh
    16. Juni 2020

    Nils Kopal via Facebook:
    Just ordered the book 🙂

  13. #13 Klaus Schmeh
    16. Juni 2020

    Bart Wenmeckers via Facebook:
    Looking forward to seeing your book in November.

  14. #14 Klaus Schmeh
    19. Juni 2020

    Richard SantaColoma via Facebook:
    I don’t think it is available for pre-order on the USA Amazon yet. But I’ll pre-order as soon as it is…